CPSC 2105 Introduction to Computer Organization
Quiz 2 Wednesday, February 14, 2007
NOTE: SHOW ALL OF YOUR WORK. YOU MUST DEMONSTRATE THAT YOU
UNDERSTAND THE PROCESS OF OBTAINING AN ANSWER. WHILE THESE CAN
BE DONE ON MANY CALCULATORS, YOU MUST DO THESE BY HAND.
1. Show the truth table for a NAND gate.
Answer:
A B AB Not (AB)
0 0 0 1
0 1 0 1
1 0 0 1
1 1 1 0
2. What does the following circuit do? Describe it using a truth table.
Answer: We begin by labeling the outputs
Here is the truth table
A B I II III C
0 0 1 1 1 0
0 1 1 1 0 1
1 0 1 0 1 1
1 1 0 1 1 0
C = A B. On the next page, I use DeMorgan’s laws to derive the expression.
Page 1 of 3 pages Answer Key 2/16/2007
